scholarly journals A Simplified Analysis Method for the Deformation Response of an Existing Tunnel to Ground Surcharge Based on the Pasternak Model

2021 ◽  
Vol 11 (7) ◽  
pp. 3255
Author(s):  
Zheng Wei ◽  
Yusheng Jiang
Keyword(s):  
Longitudinal Displacement ◽  
Maximum Displacement ◽  
Deformation Response ◽  
Reaction Coefficient ◽  
Element Simulation ◽  
Tunnel Model ◽  
Calculation Results ◽  
Pasternak Model ◽  
Boussinesq Solution ◽  
Euler Bernoulli Beam

Surface surcharge changes the existing equilibrium stress field of the stratum and adversely affects the existing tunnel. This paper presents a simplified analytical solution for calculating the longitudinal displacement of existing tunnels that are subjected to adjacent surcharge loading. Based on the Boussinesq solution, the distribution of the additional load matrix caused by the surface surcharge on the existing tunnel was obtained. A Euler–Bernoulli beam with a Pasternak foundation was used as a simplified model for tunnel stress analysis. Using the corrected reaction coefficient of the foundation bed, the differential equation of tunnel deformation was established, and the solution matrix of the longitudinal displacement of the tunnel was obtained by using the finite difference method. The reliability and applicability of the proposed method were verified by comparing the results with finite element simulation results, field test data, and the calculation results of three simplified elastic analysis methods with different foundation bed coefficients. On this basis, the parameters of the load–tunnel model were analyzed, and the effects of the buried depth, the size of the load, the relative positions of the load and the tunnel, and the relative stiffness of the tunnel soil on the maximum displacement of the existing tunnel were calculated. An empirical formula is proposed for calculating the maximum longitudinal displacement of the existing tunnel subjected to surface surcharge. The findings of this research can provide a basis for the theoretical verification of the deformation response of an existing tunnel subjected to adjacent surface surcharge.

Finite Element Analysis of the ESTELA M1 Airplane Firewall (Representative Specimen)

2011 ◽  
Author(s):  
V. Ramirez-Elias ◽  
E. Ledesma-Orozco ◽  
H. Hernandez-Moreno
Keyword(s):  
Finite Element ◽  
Federal Aviation Administration ◽  
Element Model ◽  
Maximum Load ◽  
Load Factor ◽  
Representative Specimen ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Element Simulation ◽  
The Relationship

This paper shows the finite element simulation of a representative specimen from the firewall section in the AEROMARMI ESTELA M1 aircraft. This specimen is manufactured in glass and carbon / epoxy laminates. The specimen is subjected to a load which direction and magnitude are determined by a previous dynamic loads study [10], taking into account the maximum load factor allowed by the FAA (Federal Aviation Administration) for utilitarian aircrafts [11]. A representative specimen is manufactured with the same features of the firewall. Meanwhile a fix is built in order to introduce the load directions on the representative specimen. The relationship between load and displacement is plotted for this representative specimen, whence the maximum displacement at the specific load is obtained, afterwards it is compared with the finite element model, which is modified in its laminate thicknesses in order to decrease the deviation error; subsequently this features could be applied to perform the whole firewall analysis in a future model [10].

Finite Element Simulation Analysis on Space KX-Joint

2014 ◽  
Vol 915-916 ◽  
pp. 146-149
Author(s):  
Yong Sheng Wang ◽  
Li Hua Wu
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Simulation Analysis ◽  
Local Buckling ◽  
Element Model ◽  
Ansys Software ◽  
Element Simulation ◽  
Calculation Results ◽  
Buckling Failure ◽  
The Finite Element Model

The finite element model of the space KX-Joint was established using ANSYS software, and the failure mode and ultimate bearing capacity of KX-joint were researched. Calculation results show that the surface of chord wall on the roots of compression web members was into the plastic in K plane, and the holding pole without the plastic area and the local buckling failure happened in the surface of chord wall on the roots of Compression Web Members in X plane; The bearing capacity of the joint increased with the Chord diameter, which was appears in the form of power function.

Finite Element Simulation of Metal Structure for Container Stacker Based on Ansys

2011 ◽  
Vol 94-96 ◽  
pp. 2080-2083
Author(s):  
Zhi Jian Li ◽  
Jian Kun Zhang
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Finite Element Model ◽  
Metal Structure ◽  
Element Model ◽  
Calculation Model ◽  
Ansys Software ◽  
Element Simulation ◽  
Calculation Results ◽  
The Finite Element Model

The finite element model of metal structure of 45 tons container stacker is established and Ansys software is employed to calculate the stress of key parts. The skill of model processing of the complete machine and the boundary condition of calculation model is described. The calculation results are used to guide the design of the container stacker.

Feasibility of low-cost magnetic rail designs by integrating ferrite magnets and NdFeB magnets for HTS Maglev systems

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542043 ◽  
Author(s):  
R. X. Sun ◽  
Z. G. Deng ◽  
Y. F. Gou ◽  
Y. J. Li ◽  
J. Zheng ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Magnetic Energy ◽  
Low Cost ◽  
Ndfeb Magnets ◽  
Energy Product ◽  
Element Simulation ◽  
Calculation Results ◽  
Hts Maglev ◽  
The Cost

Permanent magnet guideway (PMG) is an indispensable part of high temperature superconducting (HTS) Maglev systems. Present PMGs are made of NdFeB magnets with excellent performance and cost much. As another permanent magnet material, the ferrite magnet is weak at magnetic energy product and coercive force, but inexpensive. So, it is a possible way to integrate the ferrite and NdFeB magnets for cutting down the cost of present PMGs. In the paper, the equivalent on magnetic field intensity between ferrite magnets and NdFeB magnets was evaluated by finite element simulation. According to the calculation results, the magnetic field of the PMG integrating ferrite magnets and NdFeB magnets can be increased remarkably comparing with the pure ferrite PMG. It indicates that low-cost PMG designs by integrating the two permanent magnet materials are feasible for the practical HTS Maglev system.

Measurement of Residual Stress by Cutting Method in Cold Ring Rolling

2010 ◽  
Vol 154-155 ◽  
pp. 329-333
Author(s):  
Zhi Jiang Zuo ◽  
Le Rong Fu ◽  
Yao Li
Keyword(s):  
Residual Stress ◽  
Ring Rolling ◽  
Cutting Method ◽  
Element Simulation ◽  
Deep Groove ◽  
Cold Ring Rolling ◽  
Deep Groove Ball Bearing ◽  
Calculation Results ◽  
Bearing Race ◽  
Discharge Machine

The residual stress in cold ring rolling could cause great error to parts quality. Due to the complicated formation of residual stress, it's difficult to calculate theoretically. In present study, measurement method is generally used. According to the shape of ring, cutting method is the best method for measuring residual stress. There were 6 stages in cold rolling deep groove ball bearing race. Electric wire discharge machine was used to cut the rings after rolling in each stage. The radius of rings would change after cutting. According to the derived analytic calculation theory of residual stress, the residual stress could be calculated in different rolling stage. The residual stresses were in the range of 110-200MPa. Compared the measurement results from finite element simulation results, the greatest difference was 20%, which was in accepted rang. Through calculation results of six stages in cold ring rolling, it could found that the residual stress increased with the increase of deformation, the straightening stage was benefit to decrease residual stress.

Microstructures Finite Element Simulation of Laser Cladding Layer Regulated by Micro-Forging

2011 ◽  
Vol 328-330 ◽  
pp. 1568-1571 ◽  
Author(s):  
Ju Zhou ◽  
Chang Jun Qiu ◽  
Xi Yang Cheng
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Laser Cladding ◽  
Avrami Equation ◽  
Cladding Layer ◽  
Whole Process ◽  
Element Simulation ◽  
Calculation Results ◽  
Set Up

In the whole process of micro-forging regulation laser cladding layer, the microstructure structure of cladding layer would change. In order to establish the microstructure evolution of the whole process, firstly re-crystallization model was set up based on Avrami equation and experimental data, and various material constants were gained with regress; secondly calculation for the model was carried out on DEFORM-2D,then the results were compared with experimental data, which showed that calculation results of this model kept good consistency with experimental data, and proved that the model could be applied in a full size finite element simulation of the micro forging process.

The Finite Element Simulation of Thermal Deformation and Microstructure Evolution Forecast of AZ61 Alloy

2014 ◽  
Vol 989-994 ◽  
pp. 548-551
Author(s):  
Quan Li ◽  
Wen Jun Liu ◽  
Ren Ju Cheng ◽  
Cheng Li ◽  
Shan Jiang ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Simulation Software ◽  
The Finite Element Method ◽  
Rigid Plastic ◽  
Production Forecast ◽  
Optimization Of Process Parameters ◽  
Element Simulation ◽  
Calculation Results

In this paper, rigid-plastic finite element simulation software Marc / Auto-forge reflect compression AZ61B magnesium alloy case. Simulation results show that the stress, strain and temperature distribution within the sample is uneven, uneven distribution affect the organization, and with the changes in the deformation process and calculation results with the experimental data exactly. The finite element method can be used in the actual production forecast after tissue deformation components, optimization of process parameters to control the quality of the finished piece.

Research on Finite Element Simulation of the Big Size Spring Steel in Continuous Grooveless Rolling

2014 ◽  
Vol 941-944 ◽  
pp. 1859-1864
Author(s):  
Bao Yuan Wang ◽  
Jiang Bo Dai ◽  
Ye Hua Zhang ◽  
Da Qing Xu
Keyword(s):  
Element Model ◽  
Spring Steel ◽  
Unit Operation ◽  
Continuous Rolling ◽  
Large Size ◽  
Element Simulation ◽  
Simulation Calculation ◽  
Calculation Results ◽  
Flat Steel ◽  
Program File

T he basis of the rolling process parameters of large size spring steel for the simulation calculation ,t he fini te element model was establishe . the calculation results reveal the reasons about the billet heap and the l ow precision products , the rolling program file about continuous rolling pass and technology of the rolling mill was revised and perfect ed , the continuity and stability of the large size spring flat steel in continuous slotless roughing rolling is improved greatly, and t he unit operation efficiency increased .

scholarly journals Optimal Support Solution for a Soft Rock Roadway Based on the Drucker–Prager Yield Criteria

Minerals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Minghui Ma ◽  
Qifeng Guo ◽  
Jiliang Pan ◽  
Chi Ma ◽  
Meifeng Cai
Keyword(s):  
Internal Friction ◽  
Plastic Zone ◽  
Soft Rock ◽  
Friction Angle ◽  
Intermediate Principal Stress ◽  
Surrounding Rock ◽  
Term Strength ◽  
Maximum Displacement ◽  
Calculation Results

Through theoretical calculation, the stress and deformation of surrounding rock can be analyzed, providing guidance for the support design and optimization of soft rock roadways. In this paper, theoretical solutions for both the optimal support pressure and the allowable maximum displacement of surrounding rock are derived from the Drucker–Prager (DP) yield criteria and the steady creep criterion expressed by the third invariant of deviator stress. The DP criterion with different parameters is compared and analyzed with an engineering example. Then, based on the calculation results the effects of long-term strength, cohesion, and internal friction angle of soft rock on the maximum plastic zone radius and allowable maximum displacement of roadway are discussed. The results show that the optimal support solution of soft rock roadways based on the DP criteria can not only reasonably reflect the intermediate principal stress but can also be used to compare and discuss the influence of different DP criteria on the calculation results. The higher the long-term strength of the rock surrounding a roadway is, the smaller the optimal support force is and the larger the allowable maximum displacement is. When the calculated long-term strength of soft rock can ensure that the deformation of the roadway does not exceed the allowable maximum displacement, the roadway can maintain long-term stability without support. With an increase in the cohesion or internal friction angle of soft rock, the radius of the plastic zone decreases gradually and the allowable maximum displacement is reduced by degrees. The use of grouting and other means to improve the strength of surrounding rock can effectively reduce the roadway deformation and save support costs. This new theoretical solution can consider different intermediate principal stress effects and different DP strength criteria, enabling the parameters to become easier to determine. It has a wider range of applications, and the calculation results better demonstrate the strength potential of the surrounding rock.

Calculation Method of Intermediate Bearing Displacement Value for Multisupported Shafting Based on Neural Network

2020 ◽  
pp. 1-7
Author(s):  
Deng Yibin ◽  
Yang Xiaogang ◽  
Huang Yanling ◽  
Pan Tian ◽  
Zhu Hanhua
Keyword(s):  
Neural Network ◽  
Mutual Influence ◽  
Back Propagation ◽  
Back Propagation Neural Network ◽  
Network Training ◽  
The Neural Network ◽  
Element Simulation ◽  
Training Samples ◽  
Calculation Results ◽  
Classification Society

The mutual influence between the bearings of a ship's multisupport shafting makes its installation and alignment very difficult. This article addresses the problem of the calculation of the precise displacement value of each intermediate bearing and proposes a method for fitting the shafting characteristic function by using the GA-BP (genetic algorithm-back propagation) neural network. The neural network uses the intermediate bearing reaction as input to calculate the theoretical height of the bearing, thereby accurately calculating the displacement value. Taking the installation and alignment of a ro-ro ship's propulsion shafting as an application example, a neural network of the ship's shafting is established with training samples based on finite element simulation, and the effect of network training is discussed. The accuracy of the method is verified by a comparative analysis with the measured data of the ship's shafting. The calculation results of this method are used as a guide for the installation and alignment of the ship's shafting and have passed the delivery inspection of the classification society.

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